The stage is set and the athletes are primed as the seven-year countdown to the London 2012 Olympics reaches its finale with Friday's much-anticipated opening ceremony.
The three-hour spectacle, expected to be watched by a global television audience of up to one billion, will mark the beginning of 17 days of athletic endeavour which will create heroes, shatter dreams and fire national pride.
But London is preparing for its own intense examination as questions over the city's creaking transport system and the ever-present security threat hang over the event, ready to overshadow on-track achievements.
Prime Minister David Cameron insisted on Thursday that Britain would deliver a memorable Games after US presidential hopeful Mitt Romney backtracked on barbed comments he made about the preparations.
The Republican hopeful, in London to attend Friday's opening, said the build-up had been "disconcerting", pointing to the failure of a private security contractor to provide the number of guards it had promised.
Cameron responded by saying he was sure Britons would get behind the Games despite an economic downturn -- and took an apparent swipe at Romney's past as head of the 2002 Winter Olympics in Salt Lake City.
"We are holding an Olympic Games in one of the busiest, most active, bustling cities anywhere in the world," Cameron said.
"Of course it's easier if you hold an Olympic Games in the middle of nowhere."
Sneak previews of the £27 million ($42 million, 35 million euros) opening ceremony -- filmed at Wednesday's final rehearsal -- suggest it will be a grand but quirky production, reflecting the philosophy of director Danny Boyle.
The Slumdog Millionaire Oscar-winner has promised to create a "picture of us as a nation" and revealed the eccentric show will feature live sheep and dancing surgeons from the National Health Service.
Thousands of VIPs including some 120 national leaders are in town for the event, with guests ranging from Angelina Jolie and US First Lady Michelle Obama to the king of Swaziland.
Germany's Angela Merkel and Japanese Prime Minister Yoshihiko Noda are among the leaders set to attend while Michelle Obama will head the US delegation.
Prince William and his wife Catherine along with a flock of European royals including Prince Albert of Monaco will watch Britain's 86-year-old monarch Queen Elizabeth II officially open the Games.
Prime Minister Dmitry Medvedev will lead Russia's delegation although President Vladimir Putin has indicated he may fly in later to watch the judo, in which he is a black belt.
British football legend David Beckham said he will perform some role at the ceremony despite not being selected for Team GB, fueling gossip he may be given the honour of lighting the Olympic cauldron.
From the world of showbusiness, Hollywood mega-couple Angelina Jolie and Brad Pitt will attend after hosting a star-studded charity dinner for boxing icon Muhammad Ali on Wednesday, which counted racing driver Lewis Hamilton and actress Rosario Dawson among its guests.
Audience members at Wednesday's rehearsal promised the show would be a spine-tingling extravaganza.
The crowd at the 80,000-seater Olympic Stadium in Stratford, a previously run-down area of east London, were filled with enthusiasm as they flooded out.
"That was absolutely amazing. I wanted to whoop," said Hilary Midgley from Darwen in northwest England. "It was beyond my wildest expectations."
But with the spotlight of the world on Britain, authorities are acutely aware of the terror threat.
An additional 4,700 troops have been deployed in recent days to make up the shortfall in guards supplied by giant contractor G4S.
Anti-aircraft missiles have been placed on rooftops and a warship is anchored in the River Thames as part of the country's biggest ever peacetime security operation.
A force of more than 40,000 military and civilian personnel, backed by a huge intelligence operation, has turned the British capital into a fortress to protect venues, athletes and millions of visitors.
Cameron on Thursday stressed that security "matters more than anything else".
"I think we've made as many preparations as we can. I think we have very good contingency plans in place," Cameron said at a press conference with chief Games organiser Sebastian Coe in front of the Olympic Stadium.
Ten times Olympic medallist Carl Lewis captured the building sense of anticipation on Thursday.
"The Olympics is the only event where the world stops," he said.
"If you're the smallest country with the fewest people in the world or the biggest country with the most people in the world, everyone's allowed and everyone is invited, so it's a great thing because you get to see the world and the world sees you," he added.
